Patent GB-837996-A (GB)
Title: Metal-containing polyazo dyestuffs
IPC: C09B35/36
Filed: 1957-12-16
Abstract: The invention comprises dyes of formula <FORM:0837996/IV(c)/1> where R and R2 are coupling component radicles with O o to N2, Me is Cu, Cr, Co or Ni, R1 is a benzene or naphthalene residue with X p and O o to N2, X being a bridge containing at least two N atoms.  Indicated values for X are azo, azoxy or NHYNH, where Y is a residue of a bifunctional acylating agent.  Copper compounds are preferred.  The dyes may be made by coupling a diazotized 2-amino-6-nitro-naphthalene-4, 6-disulphonic acid with an appropriate coupling component to provide a monoazo dye which is oxidatively coppered, the nitro group is reduced to p  an amino group, the product diazotized and coupled with an o-alkoxyamino compound of the benzene or naphthalene series, further diazotizing the disazo dye thus formed and coupling with the required component and metallizing the product.  Alternatively the above copper complex may be linked with a metal complex of a nitroazo dye obtained by metallization of an appropriate monoazo dye, linking being effected by conversion of the nitro group into the bridge member, e.g. by alkaline reduction with glucose or by converting the nitro groups to amino groups and treating with acylating agents.  In the first method the nitronaphthalene di-sulphonic acid may be replaced by a corresponding acylaminoaphthalene compound and the amino group set free by hydrolysis instead of reduction.  One or two metal-free nitro dyes may be linked by methods used in the second process the products being metallized in a final stage.  In this modification a metal-free dye may be obtained by decoppering the initial coppered nitro dye. The dyes may also be made by coupling diazotized 2-amino-6-nitronaphthalene - 2,4 - di-sulphonic acid with an appropriate o-alkoxyamine and either reducing the nitro group and coupling the tetrazotized product with the required end components and finally metallizing or coupling the diazotized monoazo dye with an appropriate component, reducing the nitro dye thus obtained and diazotizing and coupling with the end component, metallization being effected as a final stage or before the last coupling.  Any demetallization that may occur when metal complexes containing nitro groups are used as reactants may be rectified by a final metallization.  Phosgene, cyanuric chloride and fumaric acid dichloride are specified acylating agents. Representative of components specified for R and R2 are 4-methylphenol, 2-naphthol, 1-naphthol-4-mono-, -3,6-di- and -3,6,8-tri-sulphonic acids, 8-ethoxy-1-naphthol-3,6-disulphonic acid, 2-acetylamino-5-naphthol-7-sulphonic acid and 1-phenyl-3-methyl-5-pyrazolone and for R1 are 1-amino-2-methoxy - 5 - methylbenzene and 2 - ethoxy - 1 - naphthylamine - 6 - sulphonic acid.  Metallization may be effected on the fibre.  The metals present may be replaced by other metals by de- and re-metallization processes.  The dyes are used on vegetables fibres, e.g. cotton. Examples are provided of the preparation of copper complexes and their use in dyeing cotton in blue or grey shades.  Specifications 660,447 and 721,495 are referred to.